The present inventions relate to an automated apparatus and method for orienting and stacking generally planar workpieces. By way of example and not limitation, the preferred embodiment of the invention described herein relates to orienting and stacking truss connector plates having a generally smooth side and a plurality of impaling members, or teeth, extending from the other side thereof.
Truss connector plates are generally planar metal plates cut from rolled or sheet steel by a punch press. Truss connector plates are usually substantially rectangular and have a plurality of teeth projecting from one side for gripping the lumber on which the truss connector plate is used. The truss connector plates also have a substantially planar backside. The truss connector plates are used to join two or more aligned pieces of lumber in the construction of a truss such as those used in wooden frame building construction.
It is known practice to orient and bundle truss connector plates to facilitate handling and shipping. The truss connector plates are arranged so that their toothed faces are aligned in tooth-to-tooth pairs. The pairs are then positioned adjacent to other pairs so that the truss connector plates of each pair are back-to-back with the truss connector plates of each adjacent pair. The truss connector plate stacks are then further handled or packaged.
It is known in the art to use automated apparatus and associated methods to produce truss connector plate bundles. Such apparatus and methods are exemplified by U.S. Pat. No. 5,636,494 to William H. Black, Jr., and by U.S. Pat. No. 5,906,264 to William H. Black et al. The prior art is an improvement over assembling bundles of truss connector plates by hand, but is complex and requires substantially different machinery for each size or number of truss connector plates exiting the punch press. Additionally, the prior art is limited to handling of either a stream of truss connector plates consisting of a single column of truss connector plates, as in Black et al., or a stream consisting of an even number of columns of truss connector plates, e.g., four, as in Black Jr.
The present inventions contemplate new automated apparatus and methods for producing stacks of generally planar workpieces output in a continuous stream from a manufacturing process. In general, the apparatus and methods include assemblies and methods for receiving, selectively flipping, and stacking generally planar workpieces. Each of the workpieces has opposing faces, a face side and a back side, and it is desired to reorient at least one of the workpieces to its opposing face, and to stack all of them.
The apparatus has a receiving assembly for receiving a continuous stream of workpieces output from a manufacturing process. A flipping assembly is located downstream from the receiving assembly for selectively flipping one or more of the workpieces to its opposing face. A stacking guide receives workpieces exiting both the flipping assembly and the receiving assembly and guides them into stacks.
The flipping assembly has a flipping arm with two selectable operative positions; a first position for receiving a work piece from the receiving assembly, and a second position for directing a work piece, once received by the flipping assembly, to the stacking guide from the flipping assembly or for allowing a work piece to enter directly to the receiving assembly. Generally, the flipping assembly is electrically connected to a flipping control assembly, which includes devices for sensing workpieces and for activating the flipping assembly according to sensor inputs and preset control instructions.
According to one aspect of the invention, the flipping assembly can be set to flip alternate workpieces in a continuous stream. According to another aspect of the invention, the apparatus can receive, orient, and stack a continuous stream of two or more parallel columns of workpieces.